Translations:Adventist Youth Honors Answer Book/Nature/Mammals/57/en

When wolves were put back into the ecosystem of Yellowstone, we learned how important one animal is in helping form a healthy ecosystem. Without wolves, the Elk could eat and drink without fear, and they had eaten most of the willow along the river. There were very few beaver left. When the wolves came back into the environment, the elk were afraid of certain areas where a wolf might hide and this allowed the willows to grow back. Now there is a growing beaver population.